A court-sworn medical expert is sometimes authorized to pass a medical judgement, whether an older, from serious diseases suffering accused is able to take part in the criminal trial proceedings. The courtsworn medical expert is required to consider the accused’s fitness, his mental and physical ability to appear in court, to understand the trial, to answer the questions of the judge, to defend himself, to put questions and objections against the witness’s testimony, etc. Such medical expert’s opinion is usually a task for a psychiatrist. Judgement of the ability of the accused to take part in the main court trial is of another character, especially when the accused is suffering from a serious disease, e.g. cardiovascular, pulmonary, gastrointestinal, haematological, tumorous or other. In this case the medical judgement is usually required from a doctor of internal medicine. Nevertheless, this is not an easy task for him. As far as these problems are concerned, the expert gathers only little experience of his own during his juridical practice. Similar cases have been extremely sporadically published in medical or juridical literature and if, then in common sense only. It is evident that the expert must face any possible aggravation of the accused’s difficulties. At the same time the expert ought to take care lest the court trial should be inadequately extended and even should prevent the accused’s avoidance in the main court trial. This paper tries to determine the basic rules for the court-sworn experts in the branch of internal medicine and would like to facilitate them to judge under which circumstances a seriously ill accused may appear in trial proceedings without exposing him to a serious damage of his health or even endangerment of his life.

        Key words: ability to undergo interrogation, ability to participate in legal proceedings, ability to undergo trial, the ill accused and the trial, medical expert’s opinion and the trial, mental stress and sudden death, mental stress and the trial.